package deserialization

import "bytes"

func InsertInto(s string, interval int, sep rune) string {
	var buffer bytes.Buffer
	before := interval - 1
	last := len(s) - 1
	for i, char := range s {
		buffer.WriteRune(char)
		if i%interval == before && i != last {
			buffer.WriteRune(sep)
		}
	}
	buffer.WriteRune(sep)
	return buffer.String()
}